Piston for internal-combustion engines



Nov. 4, 193 0.

A; LESAGE 1,780,829 PISTON FOR INTERNAL COMBUSTION ENGINES Filed July 241928 i 2 Sheets-Sheet 1 Nov. 4,. 1930.

A. LESAGE 1,780,829

.PISTON FOR INTERNAL COMBUSTION ENGINES 2 sheets-sfiaet 2 Filed' y 1928J z w Patented Nov. 4,. 1930 UNITED STATES' PATENT OFFICE ALFRED LESAGE,on BRAND-ERIBISDORF, GERMANY, ASSIGNOR 'ro' ELITE-DIM!- wnaxnAKTIENGESELLSCHAFT, or BBAND-ERBISDORF, SAXONIA, GERMANY- PISTON FORINTERNAL-COMBUSTION ENGINES Application filed July'24, 1928, Serial No.294,968, and in Germany July 27, 1927. w

The invention relates toimprovements in pistons for internal-combustionengines.

, Pistons of that type are known, which consist of light-metal, forobtaining a better abstraction of heatfrom the highly heated piston headthan at the known cast-iron pistons.

By this better abstraction of heat, a higher compression and a greaternumber of revolutions are made possible and the weight of theoscillating mass is greatly reduced.

. However such light-metal pistons offered the great drawback, that inreason of the great coefiicient of dilatation by heat of thelight-metal, they must have a comparatively great clearance in theircylinders, so that it is necessary to let the motor run light for sometime before loading it, until the pistons fit into theircylinderborings.

If, however, the engine was, loaded immediately after its starting, thepistons tended to stick in their cylinder-borings and thus very quicklybecame worn and accordingly had to be replaced by others.

It has been tried to remove these drawbacks by composing the pistons oftwo parts, namely the piston-head, consisting of lightmetal and a liner,consisting'of steel or castiron, screwedto the said piston head. Bothparts however loosened after some time of running, so that the pistonbecame waste.

In order to avoid this loosening the liner of steel has been refoundedby the light-metal ofthe piston-head. As however the piston- 'pinbearings consisted of one piece with the liner, an immediatetransmission of power from .the piston head to the piston-pins withoutany junctions cannot take place so thata beating of the junctions isthe'result. Further, the abstraction of heat from the pistonhead to thecylinder walls is a very bad one, as the light-metal of thepiston-headdoes not get into contact with the said cylinder walls.

The mentioned disadvantages of the known devices are avoided accordingto the present invention by the fact, that in a piston with alight-metal head and with a liner of hard metal, such as steel or castiron, refo'unded by the light-metal of the piston-head, that part of theliner, which is surrounded by the light-metal, forms an armature for thepiston-head, which armature is provided with openings or perforations.

In this piston the piston-pin-bearings con sist of one piece with thelight-metal-body and are arranged such in lateral openings of the liner,that they neither touch-the cylinder walls, nor the said liner.

It has been proposed, to provide in a piston for internal combustionengines a light metal piston-head, in which the light-metal of theliner, refoundetl by said piston-head,

has a greater strength than thatof the pistonhead and the samecoeificient of dilatation.

With regard to these pistons there is obtainedthe advantage by thepresentvinvention by the use of a liner with smaller coefficient ofdilatation than that of the lightmetal of the pistoighead, that thedifferent coefficients of dilatation of both parts comj pensate eachother. In consequence the ad-- vantageous efi'ects of the use oflight-metal are saved, although a great clearance of the avoided.

By the fact, that the piston-pin-bearings do not touch the cylinderwalls, a grindin between these parts in reason of elastic d E ormationsof the piston-pin-bearings cannot take place.

The abstraction of heat from the piston according to the presentinvention is as good as in pistons consisting entirely of lightmetal,and also the weight is not higher than that of the said known pistons,While the strength is equal to that of a steel-piston.

cold pistons in their cylinder-borings is '.founded in a chill by thepiston-head e which consists of light-metal. For obtaining a betterconnection, that part of the "liner, which islsurrounded by thelight-metal is provided with perforations 7.

In one piece with the light-metal body there are cast thepistonepin-bearin s g which are lying within openings h o the linerwithout being in contact with the same.

Hereby the force, exerted by the combustiongases to the piston-head istransmitted to the piston-pins Without any mechanical junctions, so thata loosening or wearing out of such junctions cannot take place. Theliner, unmovably surrounded by the pistonhead, has not to vtransmit anyconsiderable forces at its surface of contact with the light-metal, assaid liner only has to effect a lateralguiding of the piston, by whichonly frictional forces at the circumference of the liner are caused.

fixed my signature.

I-claimzi A piston for'internal combustion engines comprising incombination a light-metal head and a hard metal liner in the head, thesaid liner having perforations in the head and lateral openings in thewall for the passage of the piston'pin bearings integral with thelight-metal head while the said piston pin bearings do"not come incontact with the said lateral openings in the wall of the pistonand thecylinder wall.

In testimony whereof I ALFRED LESAGE.

have hereunto a f- Q

